This patent document relates to welding systems, devices, and processes.
Welding in large industrial applications, e.g., metal inert gas (MIG) and tungsten inert gas (TIG) pipe or plate welding, can involve welding together thick work pieces in an orbital welding process. In orbital welding, a weld head can be mounted onto, and driven by a motor to rotate continuously 360 degrees around, a work piece such as a pipe or be rotated around the pipe for 180 degrees on one side of the pipe and then repeat head rotation on the other side of the pipe. Many welding applications require precision welding, from the small standard work pieces to those of the larger scale. Orbital welding processes can be mechanized and automated, which have advantages over manual welding processes that include repeatability of consistent welds, improved welding quality, reduced operator fatigue, higher production output and lower rejection rates, and reduced difficulty to weld in tight clearances and hard-to-reach locations. For example, an orbital welding process can include a mechanized TIG welding process that joins pipe and tube segments using a clamp-on weld head in which the pipe (or tube) remains stationary and the welding torch can automatically rotate around the weld joint to complete the entire weld. The clamp-on weld head can be fixed concentric to the pipe during welding by a clamping mechanism. The clamping mechanism of the clamp-on weld head can significantly affect the accuracy of the weld. For example, unstable or misaligned attachment of the weld head to the pipe by the clamping mechanism can result in an imprecise weld, which may subsequently lead to premature fatigue, damage, or breakage.